Modular fracturing system

ABSTRACT

A modular fracturing system including a fracturing fluid manifold and a skid apparatus coupled in fluid communication with the fracturing fluid manifold and only one fracturing tree. The skid apparatus can include an inlet coupled to the fracturing fluid manifold, a single outlet coupled to the one fracturing tree via a fluid conduit, and a valve between the inlet and the single outlet to control flow of fracturing fluid from the fracturing fluid manifold through the skid apparatus to the one fracturing tree.

BACKGROUND

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the presently describedembodiments. This discussion is believed to be helpful in providing thereader with background information to facilitate a better understandingof the various aspects of the present embodiments. Accordingly, itshould be understood that these statements are to be read in this light,and not as admissions of prior art.

In order to meet consumer and industrial demand for natural resources,companies often invest significant amounts of time and money insearching for and extracting oil, natural gas, and other subterraneanresources from the earth. Particularly, once a desired subterraneanresource is discovered, drilling and production systems are oftenemployed to access and extract the resource. These systems may belocated onshore or offshore depending on the location of a desiredresource. Further, such systems generally include a wellhead assemblythrough which the resource is extracted. These wellhead assemblies mayinclude a wide variety of components, such as various casings, valves,fluid conduits, and the like, that control drilling or extractionoperations.

Additionally, such wellhead assemblies may use fracturing trees andother components to facilitate a fracturing process and enhanceproduction from wells. As will be appreciated, resources such as oil andnatural gas are generally extracted from fissures or other cavitiesformed in various subterranean rock formations or strata. To facilitateextraction of such a resource, a well may be subjected to a fracturingprocess that creates one or more man-made fractures in a rock formation.This facilitates, for example, coupling of pre-existing fissures andcavities, allowing oil, gas, or the like to flow into the wellbore. Suchfracturing processes typically include injecting a fracturingfluid—which is often a mixture including sand and water—into the well toincrease the well's pressure and form the man-made fractures. Afracturing manifold may provide fracturing fluid to wells through lines(e.g., pipes) coupled to fracturing trees of wellhead assemblies.

SUMMARY

Certain aspects of some embodiments disclosed herein are set forthbelow. It should be understood that these aspects are presented merelyto provide the reader with a brief summary of certain forms theinvention might take and that these aspects are not intended to limitthe scope of the invention. Indeed, the invention may encompass avariety of aspects that may not be set forth below.

Some embodiments of the present disclosure generally relate tofracturing systems including manifolds and skid assemblies for supplyingfracturing fluid to wells. In certain embodiments, a fracturing systemincludes dedicated skid assemblies each coupled to provide fracturingfluid to a single wellhead assembly from a shared fracturing manifold.Each of the dedicated skid assemblies can have a single fluid outletthat is coupled to a fracturing tree of its wellhead assembly via asingle fluid conduit. Such an arrangement allows the dedicated skidassemblies to be placed closely to their respective wellhead assemblies,such as directly in front of the fracturing trees of the wellheadassemblies. In some instances, the skid assemblies are coupled to anadditional manifold for providing an additional fluid to the wellheadassemblies via the single fluid outlet of each skid assembly.

Various refinements of the features noted above may exist in relation tovarious aspects of the present embodiments. Further features may also beincorporated in these various aspects as well. These refinements andadditional features may exist individually or in any combination. Forinstance, various features discussed below in relation to one or more ofthe illustrated embodiments may be incorporated into any of theabove-described aspects of the present disclosure alone or in anycombination. Again, the brief summary presented above is intended onlyto familiarize the reader with certain aspects and contexts of the someembodiments without limitation to the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of certain embodimentswill become better understood when the following detailed description isread with reference to the accompanying drawings in which likecharacters represent like parts throughout the drawings, wherein:

FIG. 1 generally depicts a fracturing system in accordance with anembodiment of the present disclosure;

FIG. 2 is a block diagram of the fracturing system of FIG. 1 with afracturing manifold coupled to multiple fracturing trees in accordancewith one embodiment;

FIG. 3 is a block diagram of a fracturing system having skid assemblieswith multiple fluid outlets for routing fracturing fluid to wellheadassemblies in accordance with one embodiment;

FIG. 4 is a block diagram of a modular fracturing system with skidassemblies each having only a single fluid outlet for routing fracturingfluid to just one wellhead assembly in accordance with one embodiment;

FIGS. 5 and 6 are plan views of fracturing systems with skid assemblieseach coupled by a single fluid conduit to a respective fracturing treeof a wellhead assembly in accordance with certain embodiments; and

FIGS. 7 and 8 are perspective views showing additional details of one ofthe skid assemblies depicted in FIGS. 5 and 6 in accordance with oneembodiment.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, all features of an actual implementation may not bedescribed in the specification. It should be appreciated that in thedevelopment of any such actual implementation, as in any engineering ordesign project, numerous implementation-specific decisions must be madeto achieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

When introducing elements of various embodiments, the articles “a,”“an,” “the,” and “said” are intended to mean that there are one or moreof the elements. The terms “comprising,” “including,” and “having” areintended to be inclusive and mean that there may be additional elementsother than the listed elements. Moreover, any use of “top,” “bottom,”“above,” “below,” other directional terms, and variations of these termsis made for convenience, but does not require any particular orientationof the components.

Turning now to the present figures, an example of a fracturing system 10is provided in FIGS. 1 and 2 in accordance with one embodiment. Thefracturing system 10 facilitates extraction of natural resources (e.g.,oil or natural gas) from a reservoir 12 via a well 14 and a wellhead 16.Particularly, by injecting a fracturing fluid down the well 14 into thereservoir 12, the fracturing system 10 increases the number or size offractures in a formation to enhance recovery of natural resourcespresent in the formation. In the presently illustrated embodiment, thewell 14 is a surface well accessed through equipment of wellhead 16installed at surface level (i.e., on ground 18). But it will beappreciated that natural resources may be extracted from other wells,such as platform or subsea wells.

The fracturing system 10 includes various components to control flow ofa fracturing fluid into the well 14. For instance, the depictedfracturing system 10 includes a fracturing tree 20 and a fracturingmanifold system 22. The fracturing tree 20 is coupled to the wellhead 16and can be considered part of a wellhead assembly, which includes thewellhead 16 and other coupled components. The fracturing tree 20 can bemounted above the wellhead 16 or can be a horizontal fracturing treeconnected to a side of the wellhead 16. Still further, the fracturingtree 20 can include at least one valve that controls flow of thefracturing fluid into the wellhead 16 and, subsequently, down the well14 to the reservoir 12. Similarly, the fracturing manifold system 22 caninclude at least one valve that controls flow of the fracturing fluid tothe fracturing tree 20 by a conduit or fluid connection 26 (e.g.,pipes).

As depicted in FIG. 2, the fracturing manifold system 22 is connected toprovide fracturing fluid to multiple fracturing trees 20 and wellheads16. But it is noted that the fracturing manifold system 22 may insteadbe coupled to a single fracturing tree 20 in full accordance with thepresent techniques. As discussed in greater detail below, variouscomponents of the fracturing manifold system 22 can be mounted on skidsto facilitate movement of the fracturing manifold system 22 with respectto the ground 18 and installation of the system 22 at a wellsite.

Fracturing fluid from a supply 28 is provided to the fracturing manifoldsystem 22. In FIG. 1, a connector 30 receives fracturing fluid from thesupply 28 through a conduit or fluid connection 32 (e.g., pipes orhoses) and then transmits the fluid to the fracturing manifold system 22by way of a subterranean conduit or fluid connection 34 (e.g., pipes).The fluid connection 34 could be provided above the ground 18 in otherinstances. In one embodiment, the fracturing fluid supply 28 is providedby one or more trucks that deliver the fracturing fluid, connect to theconnector 30, and pump the fluid into the fracturing manifold system 22via the connector 30 and connections 32 and 34. In another embodiment,the fracturing fluid supply 28 is in the form of a reservoir from whichfluid may be pumped into the fracturing manifold system 22. But anyother suitable sources of fracturing fluid and manners for transmittingsuch fluid to the fracturing manifold system may instead be used.

Components of a fracturing manifold system 40 coupled to wellheadassemblies 50 are generally depicted in FIG. 3 by way of example. Inthis embodiment, the fracturing manifold system 40 includes a fracturingmanifold line 42 coupled to skid apparatuses or assemblies 44.Fracturing fluid pumped through the fracturing manifold line 42 to theskid apparatuses 44 can be routed from fracturing fluid outlets 46 ofthe skid apparatuses 44 to the wellhead assemblies 50 through fluidconduits 52, which can be coupled to fracturing trees of the wellheadassemblies 50. In some embodiments, each wellhead assembly 50 is coupledto receive fracturing fluid from a single (i.e., only one) skidapparatus 44 by a single fluid conduit 52. But in other instancesmultiple fluid conduits 52 could be used to couple a wellhead assembly50 to receive fracturing fluid from one or more skid apparatuses 44.

Each of the skid apparatuses 44 is depicted in FIG. 3 as having fouroutlets 46, allowing the skid apparatus 44 to be connected to fourdifferent wellhead assemblies 50. In some embodiments, the skidapparatuses 44 could include a different number of outlets 46, such astwo or three. Further, the skid apparatuses 44 could have differentnumbers of fracturing fluid outlets 46, such as some skid apparatuses 44having two fracturing fluid outlets 46 and others having four fracturingfluid outlets 46. Having multiple fracturing fluid outlets 46 on theskid apparatuses 44 facilitates connection of a skid apparatus 44 tomultiple wellhead assemblies 50 and may reduce the number of skidapparatuses 44 needed at a particular wellsite.

In other embodiments, however, one or more skid apparatuses are providedwith a single fracturing fluid outlet for connection to a singlewellhead assembly. One example of such an arrangement is generallydepicted in FIG. 4. In this embodiment, a fracturing manifold system 60includes a fracturing manifold line 62 coupled to skid assemblies orapparatuses 64. The fracturing manifold line 62, like the fracturingmanifold line 42, can include various pipes and connection blocks toenable distribution of fracturing fluid to the connected skidapparatuses. Fracturing fluid received by the skid apparatuses 64 can berouted via fracturing fluid outlets 66 to wellhead assemblies 50 viafluid conduits 68.

In at least some instances, each skid apparatus 64 includes a singlefracturing fluid outlet 66, which is coupled to a single wellheadassembly 50 by a single fluid conduit 68. In such a modular arrangement,each wellhead assembly 50 can be said to have its own dedicated skidapparatus 64 and the ratio of wellhead assemblies 50 to skid apparatuses64 is one to one. Further, this modular arrangement allows eachdedicated skid apparatus 64 to be positioned directly in front of itsrespective wellhead assembly 50 (e.g., in front of a horizontalfracturing tree). This can reduce the length of the fluid conduits 68compared to other arrangements (e.g., system 40) in which skidapparatuses are shared by multiple wellhead assemblies, which canrequire longer fluid conduits to connect the skid apparatuses to moredistant wellhead assemblies. The fracturing manifold system 60 in otherembodiments could include skid apparatuses with different numbers offluid outlets for connection to varying numbers of wellhead assemblies,such as some skid apparatuses each having a single fluid outlet forconnection to a single wellhead assembly and other skid apparatuses eachhaving multiple fluid outlets for connection to multiple wellheadassemblies.

Two examples of fracturing manifold systems with modular designs aredepicted in FIGS. 5 and 6. In these embodiments, a fracturing manifoldsystem 70 (FIG. 5) and a fracturing manifold system 100 (FIG. 6) eachinclude a fracturing fluid manifold 72 coupled to skid apparatuses orassemblies 74. These skid assemblies 74 are connected by fluid lines orconduits 76 to fracturing trees 78 of the wellhead assemblies 50, with aone-to-one ratio of skid assemblies 74 to fracturing trees 78. Each skidassembly 74 includes a single fracturing fluid outlet that is connectedto one respective fracturing tree 78 by a single fluid conduit 76. Asshown here, the fluid conduits 76 include pipes and elbow joints tofacilitate connection between the skid assemblies 74 and the fracturingtrees 78. But the fluid conduits 76 may be provided in different formsin other embodiments.

Fracturing fluid can be supplied to the fracturing fluid manifold 72through an inlet 80. As depicted in FIGS. 5 and 6, the fracturing fluidmanifold 72 includes a series of pipes connected between connectionblocks coupled to and supported on the skid assemblies 74. In otherinstances, the connection blocks of the fracturing fluid manifold 72could be set back from the skid assemblies 74. The depicted fracturingfluid manifold 72 also includes a splitter 82 with valves forcontrolling flow of fracturing fluid into branch lines 84 and 86 to theleft and right of the splitter 82. Although the splitter 82 is shownhere as a two-way splitter for routing fracturing fluid to the twobranch lines 84 and 86, in other embodiments the splitter 82 could beconnected to more than two branch lines. During a fracturing operation,the splitter 82 can be operated to provide fracturing fluid to either orboth of the branch lines 84 and 86, and valves of the skid assemblies 74can be operated to supply fracturing fluid from the branch lines to thewellhead assemblies 50. In FIG. 5, the branch lines 84 and 86 are eachcoupled to the same number of skid assemblies 74, whereas in FIG. 6 thebranch lines 84 and 86 are coupled to a different number of skidassemblies 74.

In some instances, an additional manifold can be coupled to the skidassemblies of the fracturing system. For instance, in FIGS. 5 and 6, anadditional manifold 90 is coupled to the skid assemblies 74. In oneembodiment, the additional manifold 90 is a pump-down manifold forrouting fluid to wellhead assemblies 50 to pump a downhole tool (e.g., awireline tool having a plug or a perforating gun) down the wells. Theadditional manifold 90 is depicted as including a fluid inlet 92 and asplitter 94 for controlling flow of fluid into branch lines 96 and 98coupled to the skid assemblies 74. As discussed in greater detail below,in some embodiments each of the skid assemblies 74 has separate inletsconnected to the fracturing fluid manifold and the additional manifold,but has a single, common outlet for supplying fluids from the multiplemanifolds to a connected wellhead assembly 50 via a single fluid conduit76. In such embodiments, the ability to provide fluid from theadditional manifold through the same skid assemblies and out to thewellhead assemblies via the same outlets and fluid conduits used toconvey the fracturing fluid to the wellhead assemblies can eliminate theneed for separate, additional fluid connections to the wellheadassemblies to provide such fluid.

An example of one of the skid assemblies 74 is shown in greater detailin FIGS. 7 and 8. The depicted skid assembly 74 includes a flow controlassembly having various components mounted on a skid 104. A connectionblock 106 of the fracturing manifold 72 is supported on the skid 104 andcan be connected to connection blocks of other skid assemblies 74 viamanifold pipes 108. In one embodiment, the manifold pipes 108 have adiameter equal to that of the fluid conduit 76 (e.g., five andone-eighth inches). The connection block 106 is coupled to an inlet 110of the skid assembly 74. A valve 112 and a connection block 114 havingan outlet 116 is also mounted on the skid 104. The valve 112 can beopened and closed to control flow of fracturing fluid (from thefracturing manifold 72) between the inlet 110 and the outlet 116. Afluid conduit 76 can be connected to the connection block 114 at theoutlet 116 to convey fluid (e.g., fracturing fluid) from the skidassembly 74 to a fracturing tree 78 of a wellhead assembly 50, such asshown in FIGS. 5 and 6.

In at least some embodiments, such as that shown in FIGS. 7 and 8, theadditional manifold 90 includes pipes 120 and a connection block 122 forrouting an additional fluid through the outlet 116 and the fluid conduit76 to a wellhead assembly 50. The additional manifold 90 is connected toan inlet 124 of a connection block 126 of the skid assembly 74. A valve128 between the connection block 126 and the connection block 114 can beopened and closed to control flow of the additional fluid between theinlet 124 and the outlet 116. In this arrangement, the skid assembly 74includes multiple inlets for receiving fluids, but only a single, sharedoutlet 116 (common to both inlet 110 and inlet 124) for routing thefluids received from the manifolds 72 and 90 to a wellhead assembly 50through a fluid conduit 76. To facilitate connection with the additionalmanifold 90, the connection block 126 and the valve 128 can bepositioned at an angle (e.g., thirty degrees) with respect to ahorizontal plane through the fracturing manifold 72, the connection 106,and the valve 112.

The additional fluid from the manifold 90 can be used to pump a downholetool (e.g., a tool for plugging and perforating a casing in the well) toa desired position in a well. In one embodiment, this includes operatingthe valve 128 to allow fluid from a pump-down manifold 90 to passthrough the valve 128, out of the skid assembly 74 through the outlet116, and into a well (in which the tool is disposed) through a singlefluid line 76 and the wellhead assembly 50. The well can then befractured by operating the valve 112 to route fracturing fluid throughthe outlet 116, the single fluid line 76, and the wellhead assembly 50.In one embodiment, the fracturing manifold 72 is a five and one-eighthinch manifold with a 15,000 psi rating, and the additional manifold 90is a three and one-sixteenth inch manifold with a 10,000 psi rating. Butother configurations could instead be used.

In some embodiments, the skid assembly 74 is a compact skid assemblyweighing less than five thousand pounds and having dimensions of lessthan fifty inches by seventy inches by fifty inches having a borethrough the valve 112 and connection block 114 having a diameter of fiveand one-eighth inch and a 15,000 psi rating. The compact size andsingle-outlet design allows each skid assembly 74 to be placed closelyto its dedicated wellhead assembly, such as within fifteen feet orthirty feet of a fracturing tree of the wellhead assembly. This canreduce the length of pipe runs for connecting the skid assemblies to thefracturing trees. The compact size also allows the flow controlequipment of the skid assembly to be more easily accessed by operatorsat ground level, rather than having to climb scaffolding to reach upperportions of taller assemblies. This also facilitates covering of theskid assemblies with tarps or other covers to protect the assemblies inharsh conditions. Further, compared to the use of larger skid assembliesfor connecting to multiple wellhead assemblies, the use of these compactskid assemblies may reduce the expense of moving, installing, andconnecting a fracturing manifold at a wellsite. And the modular designof certain embodiments is adaptable to various well spacing orconfigurations, which can further reduce deployment expenses.

While the aspects of the present disclosure may be susceptible tovarious modifications and alternative forms, specific embodiments havebeen shown by way of example in the drawings and have been described indetail herein. But it should be understood that the invention is notintended to be limited to the particular forms disclosed. Rather, theinvention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by thefollowing appended claims.

1-11. (canceled)
 12. A fracturing apparatus comprising: a fracturingmanifold; a plurality of wellhead assemblies; and a plurality ofskid-mounted flow control assemblies, wherein the plurality ofskid-mounted flow control assemblies includes multiple modular flowcontrol assemblies each mounted on a separate skid, each coupled to thefracturing manifold to receive fracturing fluid from the fracturingmanifold, and each coupled to a wellhead assembly of the plurality ofwellhead assemblies such that the plurality of wellhead assemblies iscoupled to the fracturing manifold via the multiple modular flow controlassemblies to facilitate routing of the fracturing fluid from thefracturing manifold to the wellhead assemblies, and further wherein eachwellhead assembly of the plurality of wellhead assemblies coupled to thefracturing manifold is coupled to the fracturing manifold via adifferent modular flow control assembly that does not couple more thanone wellhead assembly of the plurality of wellhead assemblies to thefracturing manifold and the fracturing apparatus does not include anyskid having two flow control assemblies coupled between the fracturingmanifold and wellhead assemblies of different wells.
 13. The fracturingapparatus of claim 12, wherein each of the modular flow controlassemblies includes an inlet to receive fracturing fluid from thefracturing manifold and only one outlet to output the receivedfracturing fluid toward the wellhead assembly of the plurality ofwellhead assemblies that is coupled to the fracturing manifold via thatmodular flow control assembly.
 14. The fracturing apparatus of claim 12,wherein the fracturing manifold includes connection blocks mounted onthe skids of the modular flow control assemblies.
 15. The fracturingapparatus of claim 12, wherein each of the modular flow controlassemblies includes an inlet to receive fracturing fluid from thefracturing manifold and only one outlet to output the receivedfracturing fluid toward the wellhead assembly of the plurality ofwellhead assemblies that is coupled to the fracturing manifold via thatmodular flow control assembly, and wherein each of the modular flowcontrol assemblies includes an additional inlet to receive fluid from anadditional manifold and is configured to route the fluid received fromthe additional manifold to the one outlet. 16-20. (canceled)
 21. Afracturing system comprising: a fracturing manifold; a series of skidapparatuses coupled to a shared fluid line of the fracturing manifold soas to receive fracturing fluid from the shared fluid line, the series ofskid apparatuses including: a first skid apparatus having a first flowcontrol assembly mounted on a first skid and coupled to the shared fluidline, a second skid apparatus having a second flow control assemblymounted on a second skid and coupled to the shared fluid line, and athird skid apparatus having a third flow control assembly mounted on athird skid and coupled to the shared fluid line, wherein the second flowcontrol assembly is coupled to the shared fluid line downstream of thefirst flow control assembly and the third flow control assembly iscoupled to the shared fluid line downstream of the second flow controlassembly; a first wellhead assembly coupled to the fracturing manifoldvia the first skid apparatus; a second wellhead assembly coupled to thefracturing manifold via the second skid apparatus; and a third wellheadassembly coupled to the fracturing manifold via the third skidapparatus; wherein each of the first skid apparatus, the second skidapparatus, and the third skid apparatus is coupled to route fracturingfluid from the shared fluid line to only a single wellhead assembly. 22.The fracturing system of claim 21, wherein the series of skidapparatuses includes one or more additional skid apparatuses each havingan additional flow control assembly mounted on an additional skid andcoupled to the shared fluid line.
 23. The fracturing system of claim 21,wherein the fracturing manifold includes multiple branch lines and theshared fluid line is one of the branch lines.
 24. The fracturing systemof claim 23, wherein the multiple branch lines are coupled to a splitterof the fracturing manifold.
 25. The fracturing system of claim 23,wherein each of the multiple branch lines is connected to the samenumber of skid apparatuses of the fracturing system.
 26. The fracturingsystem of claim 21, comprising an additional manifold, wherein the firstwellhead assembly is coupled to the additional manifold via the firstskid apparatus, the second wellhead assembly is coupled to theadditional manifold via the second skid apparatus, and the thirdwellhead assembly is coupled to the additional manifold via the thirdskid apparatus.
 27. The fracturing system of claim 21, wherein each ofthe first flow control assembly, the second flow control assembly, andthe third flow control assembly includes two valves.
 28. The fracturingsystem of claim 21, wherein each of the first wellhead assembly, thesecond wellhead assembly, and the third wellhead assembly includes afracturing tree.
 29. The fracturing system of claim 28, wherein each ofthe first wellhead assembly, the second wellhead assembly, and the thirdwellhead assembly includes a horizontal fracturing tree.
 30. Afracturing system comprising: a fracturing manifold; skid apparatusescoupled to receive fracturing fluid from the fracturing manifold; andwellhead assemblies coupled to the fracturing manifold via the skidapparatuses to receive fracturing fluid from the fracturing manifoldthrough the skid apparatuses, wherein every wellhead assembly coupled tothe fracturing manifold is coupled to the fracturing manifold via adifferent one of the skid apparatuses.
 31. The fracturing system ofclaim 30, wherein the skid apparatuses include valves for controllingflow of fracturing fluid from the fracturing manifold to the wellheadassemblies.
 32. The fracturing system of claim 30, wherein thefracturing manifold includes connection blocks supported on skids of theskid apparatuses.
 33. The fracturing system of claim 30, wherein everywellhead assembly coupled to the fracturing manifold includes afracturing tree.
 34. The fracturing system of claim 30, wherein thewellhead assemblies are connected to the skid apparatuses with fluidconduits.
 35. The fracturing system of claim 30, comprising anadditional manifold coupled to the skid apparatuses.
 36. The fracturingsystem of claim 35, wherein the skid apparatuses include valves forcontrolling flow of an additional fluid from the additional manifold tothe wellhead assemblies.